Update srt 1.5.5

[neoxpert]

Update SRT to 1.5.5 and also add NodeJS 24 and 26 to the build matrix.

[birme]

Thanks for the update, @neoxpert! Bumping the bundled libSRT to v1.5.5 and widening the Node test matrix are both welcome.

Because this changes the libSRT version the addon compiles against (scripts/build-srt-sdk.js), it needs a maintainer to validate the native build across Linux/macOS/Windows before merging — that's our Tier B (human-merges) policy for anything touching the build script or libSRT version.

Two things to check first:

• CI now runs on pull requests as of ci: run CI on pull_request events (cover fork PRs) #80 — it previously only ran for branches inside the main repo, which is why this fork PR showed no checks. Please update this branch onto the latest master (or push a new commit); that will trigger the full build/test matrix here automatically so we can confirm libSRT 1.5.5 builds green across Node 18/20/22.
• Node 26.x isn't released yet (Node ships even majors ~April; 26 is not out as of mid-2026), so that matrix entry will fail on setup-node — could you drop 26.x for now and keep 24.x?

A maintainer will take it from here once CI is green.

Reviewed by the node-srt community triage bot — Tier B (libSRT version / build script), handed to a human maintainer.
Updated after #80 merged: CI now runs on PRs; rebase on master to trigger it.

[neoxpert]

Thank you @birme for adjusting the automated build setup.

Actually I added Node 26, as it is the current version (https://nodejs.org/en/blog/release/v26.0.0) which will also become an LTS release in October. Since the initial build pipeline run (https://github.com/neoxpert/node-srt/actions/runs/27036283376) did succeed, I kept it in the matrix.